/*
 * Copyright (c) 2015. For Intelligent Group.
 */

package com.intelligent.ispc.common.utils;

import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.*;

/**
 * Reflection tools.
 * Support to getting/call the private attribute with getter/setter methods.
 * <p>
 * Created by Peter.Li on 2015/10/9.
 */
public class Reflections {
    private static final String SETTER_PREFIX = "set";

    private static final String GETTER_PREFIX = "get";

    private static final String CGLIB_CLASS_SEPARATOR = "$$";

    private static Logger logger = LoggerFactory.getLogger(Reflections.class);

    /**
     * Invoke the Getter method.
     *
     * @param obj          target object.
     * @param propertyName property name.
     * @return property value.
     */
    public static Object invokeGetter(Object obj, String propertyName) {
        String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(propertyName);
        return invokeMethod(obj, getterMethodName, new Class[]{}, new Object[]{});
    }

    /**
     * Invoke the Setter method, just matching the method name.
     *
     * @param obj          target object.
     * @param propertyName property name.
     * @param value        property value.
     */
    public static void invokeSetter(Object obj, String propertyName, Object value) {
        String setterMethodName = SETTER_PREFIX + StringUtils.capitalize(propertyName);
        invokeMethodByName(obj, setterMethodName, new Object[]{value});
    }

    /**
     * Read object attribute directly, no matter the private/protected, don't through the getter.
     *
     * @param obj       target object.
     * @param fieldName field name.
     * @return field value.
     */
    public static Object getFieldValue(final Object obj, final String fieldName) {
        Field field = getAccessibleField(obj, fieldName);

        if (field == null) {
            throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
        }

        Object result = null;
        try {
            result = field.get(obj);
        } catch (IllegalAccessException e) {
            logger.error("Error illegal access {}", e.getMessage());
        }
        return result;
    }

    /**
     * Set object attribute directly, no matter private/protected, don't through the setter.
     *
     * @param obj       target object.
     * @param fieldName field name.
     * @param value     field value.
     */
    public static void setFieldValue(final Object obj, final String fieldName, final Object value) {
        Field field = getAccessibleField(obj, fieldName);

        if (field == null) {
            throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
        }

        try {
            field.set(obj, value);
        } catch (IllegalAccessException e) {
            logger.error("Error illegal access {}", e.getMessage());
        }
    }

    /**
     * Set object attribute directly, no matter private/protected, don't through the setter.
     *
     * @param obj       target object.
     * @param fieldName field name.
     * @param value     field value.
     */
    public static void setFieldValueWithFieldClass(final Object obj, final String fieldName, final Object value) {
        Field field = getAccessibleField(obj, fieldName);

        if (field == null) {
            throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
        }

        try {
            Class typeClass = field.getType();
            Constructor con = typeClass.getConstructor(value.getClass());
            Object param = con.newInstance(value);

            field.set(obj, param);
        } catch (IllegalAccessException e) {
            logger.error("Error illegal access {}", e.getMessage());
        } catch (Exception e) {
            logger.error("Error illegal access {}", e.getMessage());
        }
    }

    /**
     * Invoke object method directly, no matter private/protected
     *
     * @param obj            target object.
     * @param methodName     method name.
     * @param parameterTypes param type.
     * @param args           other args.
     * @return Object
     */
    public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes,
                                      final Object[] args) {
        Method method = getAccessibleMethod(obj, methodName, parameterTypes);
        if (method == null) {
            throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
        }

        try {
            return method.invoke(obj, args);
        } catch (Exception e) {
            throw convertReflectionExceptionToUnchecked(e);
        }
    }

    /**
     * Invoke object method directly, no matter private/protected
     *
     * @param obj        target object.
     * @param methodName method name.
     * @param args       other args.
     * @return Object
     */
    public static Object invokeMethodByName(final Object obj, final String methodName, final Object[] args) {
        Method method = getAccessibleMethodByName(obj, methodName);
        if (method == null) {
            throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
        }

        try {
            return method.invoke(obj, args);
        } catch (Exception e) {
            throw convertReflectionExceptionToUnchecked(e);
        }
    }

    /**
     * Get the declared field and make it to accessible one.
     *
     * @param obj       target object.
     * @param fieldName field name.
     * @return Field
     */
    public static Field getAccessibleField(final Object obj, final String fieldName) {
        Validate.notNull(obj, "object can't be null");
        Validate.notBlank(fieldName, "fieldName can't be blank");
        for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
            try {
                Field field = superClass.getDeclaredField(fieldName);
                makeAccessible(field);
                return field;
            } catch (NoSuchFieldException e) {
                // NOSONAR
                // if Field cannot be declare here, still flow up.
            }
        }
        return null;
    }

    /**
     * Get the declared field and make it to accessible one.
     *
     * @param obj            target object.
     * @param methodName     method name.
     * @param parameterTypes param class type.
     * @return Method
     */
    public static Method getAccessibleMethod(final Object obj, final String methodName, final Class<?>... parameterTypes) {
        Validate.notNull(obj, "object can't be null");
        Validate.notBlank(methodName, "methodName can't be blank");

        for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
            try {
                Method method = searchType.getDeclaredMethod(methodName, parameterTypes);
                makeAccessible(method);
                return method;
            } catch (NoSuchMethodException e) {
                // if Method cannot be declare here, still flow up.
            }
        }
        return null;
    }

    /**
     * Get the declared field and make it to accessible one.
     *
     * @param obj        target object.
     * @param methodName method name.
     * @return Method
     */
    public static Method getAccessibleMethodByName(final Object obj, final String methodName) {
        Validate.notNull(obj, "object can't be null");
        Validate.notBlank(methodName, "methodName can't be blank");

        for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
            Method[] methods = searchType.getDeclaredMethods();
            for (Method method : methods) {
                if (method.getName().equals(methodName)) {
                    makeAccessible(method);
                    return method;
                }
            }
        }
        return null;
    }

    /**
     * Change the method private/protected to public.
     *
     * @param method Method object.
     */
    public static void makeAccessible(Method method) {
        if ((!Modifier.isPublic(method.getModifiers()) || !Modifier.isPublic(method.getDeclaringClass().getModifiers()))
                && !method.isAccessible()) {
            method.setAccessible(true);
        }
    }

    /**
     * Change the method private/protected to public.
     *
     * @param field Field object.
     */
    public static void makeAccessible(Field field) {
        if ((!Modifier.isPublic(field.getModifiers()) || !Modifier.isPublic(field.getDeclaringClass().getModifiers()) || Modifier
                .isFinal(field.getModifiers())) && !field.isAccessible()) {
            field.setAccessible(true);
        }
    }

    /**
     * Get class of the generic type.
     *
     * @param clazz The class to introspect
     * @param <T>   The class to introspect
     * @return the first generic declaration, or Object.class if cannot be determined
     */
    public static <T> Class<T> getClassGenericType(final Class clazz) {
        return getClassGenricType(clazz, 0);
    }

    /**
     * Get class of the generic type.
     *
     * @param clazz clazz The class to introspect
     * @param index the Index of the generic declaration,start from 0.
     * @return the index generic declaration, or Object.class if cannot be determined
     */
    public static Class getClassGenricType(final Class clazz, final int index) {

        Type genType = clazz.getGenericSuperclass();

        if (!(genType instanceof ParameterizedType)) {
            logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType");
            return Object.class;
        }

        Type[] params = ((ParameterizedType) genType).getActualTypeArguments();

        if ((index >= params.length) || (index < 0)) {
            logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: "
                    + params.length);
            return Object.class;
        }
        if (!(params[index] instanceof Class)) {
            logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter");
            return Object.class;
        }

        return (Class) params[index];
    }

    /**
     * Get user clazz.
     *
     * @param instance the target object
     * @return clazz
     */
    public static Class<?> getUserClass(Object instance) {
        Validate.notNull(instance, "Instance must not be null");
        Class clazz = instance.getClass();
        if ((clazz != null) && clazz.getName().contains(CGLIB_CLASS_SEPARATOR)) {
            Class<?> superClass = clazz.getSuperclass();
            if ((superClass != null) && !Object.class.equals(superClass)) {
                return superClass;
            }
        }
        return clazz;

    }

    /**
     * Transfer all checked exception to unchecked exception.
     *
     * @param e exception cause.
     * @return RuntimeException.
     */
    public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) {
        if ((e instanceof IllegalAccessException) || (e instanceof IllegalArgumentException)
                || (e instanceof NoSuchMethodException)) {
            return new IllegalArgumentException(e);
        } else if (e instanceof InvocationTargetException) {
            return new RuntimeException(((InvocationTargetException) e).getTargetException());
        } else if (e instanceof RuntimeException) {
            return (RuntimeException) e;
        }
        return new RuntimeException("Unexpected Checked Exception.", e);
    }
}
